Process of freeing metals from copper



UNITED STATES PATENT OFFICE.

HATHIAS OVROM SEM, OF CHBISTIANIA, NORWAY, ASSIGNOB I10 BET NOBBKE AKTIESELSKAB FOB ELEKTBOKEMISK INDUSTBI, OF CHRISTIANIA, NORWAY, A BUSINESS ENTITY 0F CHBISTIANIA, NORWAY. i

No Drawing.

To all whom it may concern:

Be it known that I, Marmas ()vnoM SEM, a subject of Norway, and a resident of Christiania, Kingdom of Norway, have invented certain new and useful Improvements in Processes of Freeing Metals from Copper,

of which the following is a specification.

This invention relates to the removal of copper from metals containing the same. The object of the invention is a treatment of the metal whereby the copper may be entirely removed or such amounts left as may be desired.

Ores such as iron ores, nickel ores. etc, frequently contain small amounts of copper which in many cases is found in the metal manufactured from such ores. Its presence is often objectionable. Thus in the case of iron, the presence of copper is not desirable; it renders the iron brittle and unsuitable for use as steel; and in the manufacture of iron care has been taken that the copper contents do not exceed a certain amount. The metallurgists are not in entire agreement as "to the'amount of copper ermissible as a rule 0.5% Cu is consic ered a maximum. In many cases it is, however, impossible to keep the copper contents as low as desired and a special treatment of such iron will therefore be necessary to remove the copper partly or totally. I have studied this problem and have discovered a method whereby the copper contents may be eliminated or reduced to the desired degree ina convenient manner and with great economy.

I have found that when iron containing a small amount of copper in the molten condition is treated with sulphur or sulphides such as iron sulphides, silicon sulphide or other sulphides, there will always be an equilibrium between Cu in the metal and Cu in the sulphides. If a sulphide containing no or very little Cu is added to a metal comparatively rich in copper, the Cu will then move from the metal to the sulphides and, in this manner the copper contents of the metal may be brought down to any desired degree. If one treatment is not sufficient, the sulphides comparatively rich in copper may be removed and replaced by a new batch of sulphides free from copper. This treatment may be repeated any number of times until the desired result is obtained.

My process possesses special advantage Specification of Letters Patent. Patented Aug. 15, 1922.

Application filed April 4, 1919. Serial No. 287,589.

when the metal to be treated contains silicon or other elements such as carbon, phosphorus, or boron, having the property of lowering the solubility of copper sulphides in the metal. 1

For example if the metal to be freed from copper consists of iron and nickel and also contains silicon and copper, the presence of silicon will prevent nickel from entering the sulphides with which the metal is treated. Further I may in a simple manner raise or lower the contents of Ni in the metal by removing or adding silicon. If more silicon 15 present in the metal than corresponding to the following equilibria:

FeS SisFeSi S. or 2FeS 2Sis Fe,Si sis at the temperature in question, iron sulphide will decompose and form FeSiS and A3,. The FeSi will dissolve in the metal and the )ercentage of Ni will sink accordingly. If on the other hand less silicon is present in the metal than corresponding to above equilibria, that is if silicon is removed by oxidation or by other means, iron will leave the metal and enter into the sul phides, whereby the percentage of Ni in the metal is raised.

In the following specific example I have .illustrated my method using as the metal to be freed mm Cu iron containing also Ni and Si. In order to car out my invention I then roceed as fol ows:

About 500 hi ograms of iron containing 17% Si, 22% Ni. 1.2% Cu and 0.4% S are brought into a furnace which may be of any suitable type commonly used in metallurg but I prefer to use an electric furnace. In this furnace the metal is mixed with 30 kilograms. of iron sulphide containing sipproximately 64% Fe, 36% S and 0.2% u and heated to about 1450 C. At this temperature both the iron and the sulphide will be in a molten state and the desired reaction will take place resulting in the formation of copper sulphide from the copper, and iron from the iron sulphide. I have found that about one hours treatment at above mentioned temperature gives a satisfactory result. I then interrupt the heating process and remove the molten metal and the molten sulphides separately.

This may be done by first tapping the metal and then the sulphides, or in any other .45 copper which com Well known convenient manner. The iron sulphide now bein comparatively rich in Cu may of course fie treated in a separate process for the recovery of Cu.

It is to be understood that my process is not limited to above example which has en given for illustration purposes only.

he process may be carried out in similar manner if other raw materials are used.

Thus instead of using iron sulphide for the removal of copper, for example silicon sulphide or pure; sulphur or both may be employed. The sulphide to be used will of course be chosen so as to form a useful alloy from the base of the sulphide and the metal treated. If the metal in question is nickel it will therefore be advantageous to use nickel sulphide for the removal of copper or if ferronickel is desired as a final product, iron sulphide may be used. In above Specific example I have heated to a temperature of about 1450 C. The temperature material in question. In order to obtain a result a temperature above said melting goint will generally be required.

p e foregoing detailed description has been given for clearness of understanding and no undue limitation should be deduced therefrom, but the ap ended claims should -be construed as broa 1y as permissible in view of the prior art. I

'What I claim as new and desire to secure by Letters Patent of the Unit-ed States is:

1. The process of freeing metals from copper which comprises heating a metal contami copper to above its melting point 40 and su jecting it to the action of sul bar in the form of a sulphide of the sai metal whereby copper sul hide is formed, and separatin said sulphi e from the metal.

- 2. 'fiie process of freeing metals from rises heating iron contammg copper an also containing silicon to above its melting point and subjecting it to the action of sulphur, whereby copper sulphide is formed, and separating said sulphide from the metal.

, a 3. The process of I freeing metals from copper which comprises heating iron contalnmg copper and also containing silicon to above its melting point and subjecting it to the action of sulphur in the form of a taming sulphide, whereby copper sulphide is formed, and separating said sulphide from the metal.

4. The process of freeing metals from copper which comprises heating iron containing copper andv also containing silicon to above its melting point and subjecting it to the action of sulphur in the form of an iron sulphide, w ereby copper sulphide is formed, and separating said sulphide from the metal.

5. The rocess of freeing metals from copper Whicli comprises heating iron containmg copper'and also containing silicon and nickel to above its melting point and subjecting it to the action of sulphur, whereby cop r sulphide is formed, and separating said zulphide from the metal.

6. The process of freeing. metals from copper which comprises heating iron containing copper and also containing silicon and nickel to above its meltin point and subjecting it to the action of su phur in the form of a sulphide whereby copper sulphide is formed, and separating said sulphide from the metal. I

T. The process of freeing metals from copper which com rises heating iron containing copper an alsocontaining silicon and nickel to above its melting point and subjecting it to the action of sulphur in the form of an iron sulphide, whereb copper sulphide is formed, and separating said sulphide from the metal.

The process of freeing metals from copper which comprises heating iron containing copper and also containing silicon-to substautially 1450" C. to 'ther with an iron sulphide, said iron. su phide reacting with the metallic copper present resulting in the formation of copper sulphide and metallic iron, and separating said sulphide from the metal.

'9. The process of freeing metals from copper which comprises heating iron concopper and also containing sihcon and nickel to substantially 1450 C; together with an iron sulphide, said iron sulphide reacting with the metallic copper present resulting in the formation of copper.

sulphide and metallic iron, and separating said sul hide from the metal.

Signed at Christiania, Norway, this 18th day of March 1919.

. MATHIAS OVROM SEM. 

